Nano/microparticles have been actively pursued as an efficient way for drug delivery. Therefore, quantitative measurement of cellular uptake of nano/micro particles is of great importance in understanding the mechanisms of cell endocytosis and exocytosis process. (B. D. Chithrani, A et al., Nano Lett. 2006, 6, 662; B. D. Chithrani, W. C. W. Chan, Nano Lett. 2007, 6, 1542; F. Osaki, et al., J. Am. Chem. Soc. 2004, 126, 6520; J. A. Champion, S. Mitragotri, Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 4930; H. Jin, et al., ACS nano 2009, 3, 149.)
The conventional ways for quantifying nano/micro particle uptake into mammalian cells involve both inductively coupled plasma atomic emission spectroscopy (ICP-AES; B. D. Chithrani, et al., Nano Lett. 2006, 6, 662; B. D. Chithrani, W. C. W. Chan, Nano Lett. 2007, 6, 1542; F. Osaki, et al., J. Am. Chem. Soc. 2004, 126, 6520; J. A. Champion, S. Mitragotri, Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 4930; H. Jin, et al., ACS nano 2009, 3, 149; J. A. Ryan, et al., Anal. Chem. 2007, 79, 9150) and inductively coupled plasma mass spectrometry (ICP-MS; P. Yang, et al., Bioconjugate Chem. 2005, 16, 494). These are accurate but are limited to elemental species, such as gold nanoparticles (NPs). Recently, laser desorption/ionization mass spectrometry has been employed to achieve quantitative measurements of gold NPs uptake by cells with the gold NPs encoded with different functional groups as mass barcodes. (Z.-J. Zhu, et al., J. Am. Chem. Soc. 2008, 130, 14139) However, the encoding process is tedious and time consuming.
There is a need to provide a rapid means for quantifying nano/micro particle uptake into mammalian cells. There is a need for a means for quantifying uptake into mammalian cells of all types of nanoparticles including non-metallic nano/micro particles such as polymeric nanoparticles (NPs), liposomes, viral-based NPs, carbon nanotubes, diamond NPs, and polymeric micelles. Further, there is a need for a means for quantifying uptake into mammalian cells of all types of pathogenic nanoparticles including, but not limited to, viruses, bacteria, prions, yeast, fungi, and parasites.